Removing Sound Deadening

Removing sound deadening is something that has caught on a little bit more than anticipated. Race cars have always been stripped of all unnecessary weight in order to accelerate, handle, and stop better. Recently, especially among the Japanese import car scene, street cars have begun to lose weight. It always starts small and innocently enough, maybe the rear speakers and amplifier come out first. Followed by the back seats, and then the floor mats. Suddenly, everything is coming out.

Every car guy will have differing opinions on what exactly constitutes a "streetable" car. Some say go ahead and strip everything except the dash and front seats. To loud or hot inside the car? Harden up! Other guys strip everything behind the front seats. At the end of the day, it comes down to how much comfort you are willing to sacrifice in the pursuit of performance.

When it comes to automotive sound deadening, you're looking at anywhere from 20 pounds spread throughout the car, to in excess of one hundred pounds in more luxury oriented cars. If you are planning on stripping the interior of your ride, you can't look at individual weights of removed parts. Rather, you need to look at all removed parts as a whole. Removing two rear factory speakers may save ten pounds. Not enough to notice a difference on their own. But add that ten pounds to the seventy five pounds you have removed so far, and suddenly you've stripped eighty five pounds. The whole picture needs to be taken into account when removing lighter items. In the end, it can make a noticeable difference when all added up!

This how-to article deals with the art of removing sound deadening using a hammer, chisel and elbow grease. There are two ways to strip sound deadening, the easy way and the hard way. The easy way involves sourcing some dry ice to put the deadening tar into a super frozen state making it easy to bash off with a hammer. The hard way involves a hammer, a chisel, and depending on your car, as much as twenty hours of spare time. Today, we're doing it the hard way.

Chisels Gonna Chis

Remember to hit the chisel, not your fingers

Hammers Gonna Ham

This is a hammer. Everyone loves hammers!

Brakekleen gonna.. Well, you know.

NON CHLORINATED Brake Kleen is amazing.

Tools of The Trade

Here is the list of tools you need to complete this job. One of them can be found in nearly every household on the planet. The other might not. I had both handy.

Hammer

Chisel

Brake Kleen or WD40

I'll assume you have a hammer and a chisel ready. If not, they are both inexpensive to purchase from any department or home improvement store. I wouldn't be surprised if grocery stores were selling hammers nowadays, as well. If you are extra cool, you'll have a pneumatic chisel powered by an air compressor. This will make your life easier. But I can't imagine to many people have pneumatic chisels.

In the interest of safety, make sure you hit the chisel, not your fingers, with the hammer. Very few things feel worse than a hammer smashed finger.

You are going to use the Brake Kleen (or WD40 if you prefer that) to do the final clean to the now brown, residue covered metal that remains after removing sound deadening.

Use non-chlorinated Brake Kleen. Any manufacturer is fine, just make sure it's non- chlorinated. It stinks so try to find non-odorized versions, as well.

Chlorinated brake kleen is fine if you don't plan on doing any welding on or near the area where the Brake Kleen was applied. The heat of a welding torch can incite a chemical reaction that creates a gas so deadly, you could very well be dead before you hit the ground. The gas is so deadly, that it was used very effectively on the battlefields during World War One.

The Sound Deadening

Ugly black tar will eventually reveal a shiny metal floor | Source

As you can see, the tar is everywhere the manufacturer (Nissan, in this case) wanted to suppress sound. The deadening in the rear of this car was thickest on the transmission tunnel and the wheel arches. The sound deadening tar along the floor is quite thin, not much noise to surpress in those areas, perhaps?

Time to Start Removing That Sound Deadening

The first bit of deadener chiseled off will make you realize that no, this is not a job that's going to be done in time for dinner. You may even feel slightly apprehensive as the first piece chips off. The trick is to dedicate at least a few hours a day to chiseling the stuff away. If you try to do it all at once, you're going to begin to hate life very, very quickly. Your back will probably be sore, too.

Tips:

For your own sake, don't undertake the hammer and chisel method if it is hot out. If you live in a hot climate, you might want to use the dry ice method. The hotter it is inside the car, the more "goopy" the sound deadening tar will be. Which makes it horrible to remove with hammer and chisel.

Depending on the size of your car as well as its shape, you may find it easier to remove the front seats to allow for extra room to maneuver. Be careful if not to throw your back out lifting the seats out if they are OEM, they will be heavy.

Begin chiseling from the edges and work your way in. Small scratches exposing the bare metal underneath are going to happen, it's a sad fact of chiseling. After you've completed the job, you'll want to prime and paint anyway, so don't worry about those jagged scratches. They'll be invisible by the time you're done.

You will get to sticky parts that are very difficult to scrape off. Move on and come back to those spots when everything else is done. You may require different tools at the point.

Small bits of tar will be stuck to the floor everywhere, just go for the pieces bigger in size than a dime for now. Those pieces will be scrapped off later.

Remember to take breaks, especially if you're not enjoying your manual labor. Listening to music helps, as does whistling a tune or thinking about something other than chiseling sound deadening.

If you are interested in knowing how much weight you have removed after you've finished chiseling the sound deadening, keep a plastic bag handy and put all of the chipped off bits in the bag. You'll be surprised how heavy the bag is after you've completed the project.

Change sitting positions frequently. It doesn't take long to start developing sore knees or an aching back while hunched over inside a car.

You will get done. It might look like an impossible long project after that first chipped piece of sound deadening flies off and nearly hits you in the face, but it can be finished: Harden up!

Here's how it will look at this stage

This is what you will be left with.

Now that you have successfully stripped your sound deadening out, it's time to deal with the gross little bits that are still hanging on to the chassis for dear life. There are a few ways to deal with these guys. You can continue to use your trusty chisel, only without the hammer this time, using it to scrape the remaining bits off the car. I found that this was the fastest way to go about things. Others have had better luck using a putty knife. I tried that but didn't find it to successful.

Some people use a blow dryer to heat the remaining bits up slightly, making it much easier to remove them. I didn't do this as it was pouring rain and I didn't want electrical cords running through puddles out to my car. If you like, you can try it out and report back with the effectiveness by leaving a comment.

Once you have (finally!) managed to get the last of the sound deadening tar removed from the chassis, you'll probably notice just how ugly it looks, with some type of brown residue left over that doesn't wipe off. This is where the Brake Kleen and/or WD40 comes in. When using Brake Kleen or WD40, you want to ensure that you have adequate (I prefer excellent) ventilation. Open all doors, the trunk (if the trunk and passenger compartment are connected as one), and the sunroof if you have one. If you want to go the extra mile, set up a fan to blow the fumes out one of the doors. Or disregard all of this advice and end up with a massive headache and nausea the way I did the first time.

Using your cleaner, spray a dab on to a clean rag. Now scrub a bit to see how well the residue comes off. It will mostly likely come off in the first swipe. Now using a clean part of the rag, spray another blast of your cleaner onto the rag and clean another spot. Doing this, while ensuring you are always using a clean part of the rag, ensures you will be getting rid of the residue, not just moving it around creating brown streaks everywhere.

Sound deadening is almost completely removed

Looking much cleaner now! Still a ways to go on my ride, though. Trunk still needs to be done!

Nearly There!

You will always have a few spots that continue to hold glue and/or residue despite your industrial grade cleaners and copious amounts of chiseling and scraping. The yellow spots seen on the floor of the car in the picture above are actually a sticky, very dense glue material that have to be removed using either heat and a chisel, or a very fine putty blade. Either way, it will take a while to completely remove it all.

Now that you have removed your sound deadening, you (hopefully) have quite a heavy bag nearby. This will be your trophy. You can go and put it on your scale to measure the success of your victory. If it doesn't register, weigh yourself, then weigh yourself again holding on to the bag. Subtract the difference from the number. Keep in mind that most digital bathroom scales have low accuracy, so your bag might be heavier than is indicated.

So there you have it. You no longer have rear sound deadening! Go for a drive and see how it feels. You are going to have more road noise, but you already knew that, right? Drive over some gravel to gauge just how loud your car is with rocks and gravel bouncing up and hitting the now-naked wheel wells. Sounds like a race car, right? Don't worry, you eventually get used to the noise and won't notice it anymore.

Final tips

You will probably be left with small holes here and there that let you see the ground beneath your car. You can fill these in using rubber grommets (like the ones in the picture above), or you can do it on the cheap and use duct tape on the interior and exterior above the hole. Alternatively, you can fiberglass the holes shut. Just don't bondo them, it will crack in no time.

That slight high sensation you felt after using Brake Kleen or WD40 without adequate ventilation is the sensation of your brain cells dying, so don't do it again, please!

For maximum benefit, couple this weight decrease with the removal of the rear seats, spare tire and jack, at the very least. It all adds up in the end, and will be noticeable on the street and track.

The rule of thumb is that for every 100 pounds of sprung weight you remove (things like deadening, spare wheels, seats, etc), you will "gain" roughly ten horsepower, and lower your quarter mile time by one tenth of a second. Therefore, a car with 200 horsepower that loses two hundred pounds of sprung weight will accelerate like a car that has 220 horsepower. If that car could do a 15 second quarter mile as stock, it can now do a 14.8 second quarter mile.

As irrelevant as I feel this is: Girls won't like your car very much, now. They're going to complain that it's too noisy. It's your car, though. If they don't like it, they can walk!